Utilizing Computational Modeling to Aid the Development of a Wearable Soft Robot for Finger Rehabilitation

Abstract

As more people suffering from mobility impairments, there are growing needs for rehabilitation. Rehabilitation robots have been proven to be effective in assisting patients in their rehabilitation process. However, many existing rehabilitation robots are costly so the accessibility to the patients in need is limited. Our team has been working on a proof-of-concept soft robot design that could be used for finger rehabilitation. Our eventual goal for this soft robot concept is to lower the barrier to access rehabilitation. Hence, our soft robot is designed unlike most other existing soft robots, which are actuated by external components. Our soft robot is completely untethered and actuated by heat. Using a phase changing material (PCM) sealed in elastomer compartments as the working fluid for our soft robot, when heat is applied, the PCM begins to change phase and the pressure inside the sealed elastomer compartments increases to bend our soft robot. Because the bending of our soft robot is closely related to the pressure increase inside of the elastomer compartments, we use computational modeling to investigate that correlation. In this paper, we present the CFD (Computational Fluid Dynamics) and FEA (Finite Element Analysis) simulation models we studied. CFD simulation helps us investigate how the pressure to increase inside of the elastomer compartments when PCM changes phase and FEA modeling further identifies the bending angles for a given pressure inside of the elastomer compartments. These modeling results would aid the development of our soft robot prototypes in the future.